<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<style>
div {
	border:1px solid #000;
	width:100px;
	height:100px;
	margin:10px;
	float:left;}
</style>
<script>
window.onload=function ()
{
	var aDiv=document.getElementsByTagName('div')
	//alert(aDiv.length)弹出div框数，共4
	//aDIv.style.background='red'
	//没用，因为div有多个
	/*
	aDiv[0].style.background='red'
	aDiv[1].style.background='red'
	aDiv[2].style.background='red'
	aDiv[3].style.background='red'
    */
	for(var i=0;i<aDiv.length;i++)
	{
		aDiv[i].style.background='red';
	}
}
</script>
</head>

<body>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
</body>
</html>
